Current connection for electric lamps.



l. A. ORANGE. CURRENT CONNECT ION FOR ELECTRIC LAMPS.

- APPLICATION HLED DEC. 26. 1914. 1.-,209,014=. Patented De0.19,1916. 2 SHEETS-SHEET 1- Fig.4.

Witnesses: I Inventor:

.John 3 Orange,

His fitfoorneg.

J. A. ORANGE. ENT CONNECTION FOR ELECTRIC LAMPS.

APPLICATION FILED DEQZG. I914.

' Patented Dec.19,1916.

2 SHEETS-SHEET 2- CURR Inventor; John D .Ofan Qe,

. His; JTttor ey.

I Witnesses:

ens rnrn'r ornion.

JOHN ARTHUR ORANGE, OF SCHENECTAIDY, YORK, AS-SIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CURRENT CONNECTION FOR ELECTRIC LAMPS.

Specification of Letters Patent.

Patented Dec. 19, 1916.

To all whom it may concern:

Be it known that 1, JOHN ARTHUR ORANGE, a subject of the King of Great Britain, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Current Connections for Electric Lamps, of which the following is a specification.

My invention relates to current connections such as are used for electric lamps and the like, and it includes both bases or plugs and corresponding sockets or receptacles that are especially suitable for the mounting and electrical connection of such lamps, though also applicable and adaptable to other uses.

The invention is more particularly concerned with the transmission of such relatively heavy currents as are required by high candle power tungsten filament incandescent lamps containing nitrogen, or other gas or vapor and operating at very high efliciency. It is important that when such a lamp is inserted in a socket or receptacle each of the connections necessary to complete its circuit should be made with good contact over ample area, in order that the parts shall not be liable to injurious or dangerous overheating, and also for other reasons. How this and other requirements can be met and various advantages obtained through my invention will appear from the following discussion and from the detailed description of particular embodiments hereinafter, While its scope will be indicated in my claims/ In accordance with my invention, I secure good contact and current carrying capacity by providing the base or plug device with terminals having coacting screw threaded contact surfaces and providing the socket or receptacle device with terminals having corresponding screw threaded contact surfaces, so that each of the connections necessary to complete the circuit is a screw threaded connection. Good contact and pressure over an adequate area can be insured between corresponding base and socket contact surfaces if the terminals of one of these connection de-.

vices are made movable relatively to one another (in some degree at least) when engaging those of the corresponding device and the base and socket terminals are so related that such movement must necessa i y occur; and when a base is screwed into a socket relative mobility of coacting terminals will also tend to compensate for any initial lack of correspondence between screw threads. As regards mobility, one of the socket terminals may be axially movable in either direction, or may be capable of rotary movement; and as to insuring relative movement or displacement, this can most readily be done by making the coacting threads of each connection device of different pitches. The movable or floating socket terminal may advantageously be arranged or constructed to resist movement or displacement by the corresponding base terminal, and may preferably be resiliently or elastically yielding in its resistance. However, with differential threading of the terminals good contact and pressure can even be secured without any relative movement, as will hereinafter appear. 7

In the accompanying drawings, Figure l is a fragmentary view, partly in section, showing a lamp with a base constructed in accordance with my invention; Fig.2 is a receptacle shown'in Fig. 2; Fig. 4 is a perspective exterior view of the receptacle shown in Fig. 2; Fig. 5 is a bottom view of the receptacle shown in Figs. 2 and 4:; Fig. 6 is a fragmentary sectional view illustrating a form of lamp base different from that shown in Fig. 1; Fig. 7 is a mid-sectional view illustrating a socket adapted to take the base shown in Fig. 6; Figs. 8, 9, and 10 are views illustrating details of construction; Fig. 11 is a sectional detail view illustrating a modification of certain parts of the construction shown in Fig. 7.

As shown in Fig. 1, the terminals of the lamp base 31 consist of two electrically separate screw threaded shells 32 and 33 of different diameters or sizes, arranged coaxially terial which tern ally 'sulating covering 46 is screw threads of the large terminal 32 is made greater than that of the threads of the small terminal 33. The terminal 32 may be of the same size as the screw shell of the base commercially known as the Mogul, and the terminal 33 of the size of the screw shell of the ordinary medium base, and the insulating material 34 may unite them me-' chanically to one another and to the enlarged skirt 35 in the manner illustrated in U. S. Patent No. 775,689 to Swan, granted November 22, 1904. As shown, the terminal shell 33 is not made as a closed cap, but with an open lower end from which the insulation 34 projects enough to insure against the production of a short circuit if an ignorant person should screw the lamp into an ordinary medium screw socket.

Referring to Fig. 2, it will be seen that the socket or receptacle device 41 for the base or plug device 31 has screw shell terminals 42 and 43 which are arranged one within the other with their coacting internal differentially screw threaded contact surfaces coaxial and are movable relatively to one another when engaging the corresponding base terminals 32 and 33. The terminals 42 and 43 are mounted on a body structure 44 of porcelain, bisque, or other insulating maforms a casing about them, the large terminal 42 being fixedly secured by screws 45, while the small terminal 43 is spring mounted so as to be resiliently yielding in an axial direction. As shown, the terminal shell 43 is in the form of a cup with an angular hole in its bottom, and it is exinsulated by an inclosing cup or cap-like shell 46 of fiber, porcelain, bisque, or other insulating material. For mounting the movable or loose terminal 43 with its inemployed a stud 47 (see Fig. 3) formed of sheet metal suitably punched, bent, and riveted, etc. The head of this stud 47 lies at the bottom of the terminal 43 and may be soldered or otherwise fastened to it, and its angular yoke-like shank 48 extends through angular holes in the parts 43 and 46 and through a similar hole at the bottom of a circular recess in the base portion of the body structure 44. A heavy helical compression spring 49 in this recess around the shank 48 urges the terminal 43 with its associated parts outward toward the mouth ofthe large terminal 42. The outward movement of the terminal 43 is limited by a piece 50 secured by a screw to the shank 48 and projecting beyond the edges of the hole in the body structure 44 through which said shank extends, while its inward movement is limited by the body structure 44 itself.

Referring to Figs. 2, 4, and 5, it will be seen that the insulating body structure'44 is provided with a pair of lugs or feet, 51 pierced to receive sc ews for secur ng the socket in position, and also with lugs 52 that carry binding posts 53, 54 for the connection of the current supply wires. From the binding post 53 electrical connection to the terminal 42 is through two screws 55, a metal piece 56 in a recess at the bottom of the body structure 44, and two of the screws 45; from the binding post 54 it is through two screws 57, a metal piece 58 with which they engage, and a flexible laminated lead 59 composed of a number of thin copper strips soldered to said piece 58 and clamped to the shank 48 by the piece 50.

It will be seen that the movable or floating terminal 43 with its associated parts is restrained or prevented from turning relatively to the terminal 42 and its associated body structure 44 by the engagement of the shank 48 with said body structure, and that axial movement or displacement of said terminal 43 from the position shown (which in the absence of a lamp is its normal one) is yieldingly resisted by the spring means 49. hen the base 31 is inserted in the socket 41 and turned clockwise, it comes into concurrent threaded engagement with both of the socket terminals 42 and 43; but the socket parts are preferably so proportioned and ar; ranged that meshing and engagement occur between the terminals 32 and 42 sooner than between the terminals 33 and 43, because with this action any failure of the terminals 33 and 43 to mesh when they first come in contact (owing to defective workmanship or error in assembling the parts) will not cause a jamming, but merely result in the loose or floating terminal 43 being forced inward rather rapidly by further turning of the base until the terminal 33 does mesh and engage with it properly. Once the terminals 32 and 42 and 33 and 43 are in threaded engagement, further turning of the base 31 will force the loose terminal 43 slowly inward at a rate depending on how much less its pitch is than that of the terminal 42, and the resulting progressive compression of the spring 49 will cause a progressively increasing binding effect upon the engaging screw threaded terminals. The final or limiting condition will preferably be at the inner limit of movement of the terminal 43.

1t will be seen that when the base 31 is screwed well into the socket 41 the compression of the spring means 49 (if it be a fairly stiff strong spring of suitable scale) resulting from the differential threading of the terminals will insure good contact pressure over a large area. The spring 49 can, however, be dispensed with or made too weak to produce such pressure and a good result obtained if the base 31 is simply screwed into the socket 41 until the floating socket terminal 43 is firmly jammed or wedged at the inner limit of its movement,-the parts being, of course, so designed that such jam g ll screw threads may be occur before the base terminal 33 bottoms in the socket terminal 43. Again, movement of the socket terminal 43 may be blocked or entirely done away with if the difference of pitch between the terminals 32 and 42 on the one hand and the terminals 33 and 43 on the other is made small and the backlash or play between base and socket threads is made large, so that the base 31 can be screwed far enough into the socket 41 before jamming occurs.

When the socket terminal 43 is movable and the spring 49 is used, compression of the the differential action of the supplemented by purposely so arranging the socket terminals 42 and 43 relatively to one another and to the base terminals that when the base is screwed into the socket the base terminal 33 will not spring by mesh and engage with the movable socket terminal 43 when it first encounters it, but only after it has forced it inward a certain distance.

The lamp base 61 represented in Fig. 6

5 differs from that shown in Fig. 1 in having its coacting differentially threaded screw shell terminals 62 and 63 arranged coaxially one within the other. The corresponding socket or receptacle 71 has its coacting differentially threaded screw shell terminals 72 and 73 also arranged coaxially one within the other. The large socket terminal 72 is fixedly secured in place against a remova'ble insulating wall that rests against a shoulder in the insulating body structure 74 by a suitable number of bolts 75,one of which forms part of its current connection and has a binding nut 7 6 for securing a current lead. The movable or floating socket terminal 73'is secured on an insulating part 77 by a bolt 78 which is included in its current connection. This bolt 78 also secures to the part 7 7 a disk 7 9 to which a weight 80 .is in turn secured by screws 81. The current connection to the movable terminal 73 includes a laminated flexible conductor 82 of U shape, and one of its ends is clamped beneath the nut on the bolt 78 while the other is clamped beneath the head of a bolt 83 which has a nut 84 for securing another current lead.

The weight 80, it will be seen from Figs.

7, 9, and 10, is in the form of a ring with inwardly extending lugs 85 for the screws 81.

In the upper end of the body structure 74 are recesses 86 (see Fig. 8) which receive the lugs 85, and there are similar recesses on the lower side of the insulating upper piece 87, which is secured to thebody 74 by the bolts and 83. When the base 61 is screwed into the socket 71, the weight is raised by the differential action of the screw threads and plays the part of the spring 49 of Fig. 2,the principal difference being that the resistance of the weight and the re such contact occurs will merely jam or wedge the parts tighter and tighter and increase the contact pressure on the terminals.

In the modified construction illustrated in Fig. 11 the role of the weight 80 is taken by the shade-holder 90 and the attached shade 91, which is here shown as a sheet metal one bolted to the shade-holder. Also, the movable screw shell terminal 93 is directly attached to the disk 99 corresponding to the disk 7 9 of Fig. 7. Parts corresponding to the screw shell 72, insulating body structure 7 4, and the insulating piece against which the screw shell 72 is bolted are omitted to avoid confusion. In other respects and as regards parts not illustrated this construction involves no material differences from that of Fig. 7, except that the part 97 extends down over the part 90 in the form of a water-shedding hood.

While I have, in accordance with the requirements of the patent statutes, shown and described the best form of embodiment of my invention, I do not desire to restrict myself thereto; moreover, I hereby wish to disclaim inventorship of the broad idea of coacting threaded contact surfaces of different diameters and the relatively moving or floating terminal, the same being respectively the inventions of Howard B. Sargent and Frederick H. Weston.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. A connection comprising a base or plug device having terminals with coacting differentially screw threaded contactsurfaces and a socket or receptacle device having terminals with corresponding screw threaded contact surfaces, said socket terminals being relatively movable and so related to 4:. A connection device comprising termidiameters for concurrent threaded engage- Y ment with threaded terminals of a corresponding socket.

6. A high current base comprising terminals with coacting external difierentially screw threaded contact surfaces of different diameters for concurrent threaded engagement with threaded terminals of a corresponding socket.

7. A high current socket or receptacle comprising terminals with coacting internal differentially screw threaded contact surfaces of different diameters for concurrent threaded engagement with threaded terminals of a corresponding base.

8. A high current socket or receptacle comprising terminals with coacting coaxial differentially screw-threaded contact surfaces of different diameters, said terminals being axially movable relatively to one another to a limited extent.

9. A high current socket or receptacle comprising terminals with coacting differentially screw-threaded contact surfaces, one of said terminals being fixed and the other movable axially, and means yieldingly resisting such movement.

10. A socket Or receptacle comprising terminals with coacting differentially screwthreaded contact surfaces of different diameters, said terminals being resiliently yielding relatively to one another when coming into engagement with those of a correspond ing base.

11. A socket or receptacle comprising terminals with coacting coaxial differentially screw-threaded contact surfaces of different diameters, the larger of said terminals being fixed and the smaller spring mounted so that it may yield axially.

In witness whereof, I have hereunto set my hand this 24th day of December 1914.

JOHN ARTHUR ORANGE.

Witnesses BENJAMIN B; HULL, HELEN Onrom).

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

